﻿// Copyright 2013-2016 Serilog Contributors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

using System;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyModel;
using Serilog.Configuration;
using Serilog.Settings.Configuration;
using Serilog.Settings.Configuration.Assemblies;

namespace Serilog
{
    /// <summary>
    /// Extends <see cref="LoggerConfiguration"/> with support for System.Configuration appSettings elements.
    /// </summary>
    public static class ConfigurationLoggerConfigurationExtensions
    {
        /// <summary>
        /// Configuration section name required by this package.
        /// </summary>
        public const string DefaultSectionName = "Serilog";

        /// <summary>
        /// Reads logger settings from the provided configuration object using the provided section name. Generally this
        /// is preferable over the other method that takes a configuration section. Only this version will populate
        /// IConfiguration parameters on target methods.
        /// </summary>
        /// <param name="settingConfiguration">Logger setting configuration.</param>
        /// <param name="configuration">A configuration object which contains a Serilog section.</param>
        /// <param name="sectionName">A section name for section which contains a Serilog section.</param>
        /// <param name="dependencyContext">The dependency context from which sink/enricher packages can be located. If not supplied, the platform
        /// default will be used.</param>
        /// <returns>An object allowing configuration to continue.</returns>
        public static LoggerConfiguration Configuration(
            this LoggerSettingsConfiguration settingConfiguration,
            IConfiguration configuration,
            string sectionName,
            DependencyContext dependencyContext = null)
        {
            if (settingConfiguration == null) throw new ArgumentNullException(nameof(settingConfiguration));
            if (configuration == null) throw new ArgumentNullException(nameof(configuration));
            if (sectionName == null) throw new ArgumentNullException(nameof(sectionName));

            var assemblyFinder = dependencyContext == null
                ? AssemblyFinder.Auto()
                : AssemblyFinder.ForDependencyContext(dependencyContext);

            return settingConfiguration.Settings(
                new ConfigurationReader(
                    configuration.GetSection(sectionName),
                    assemblyFinder,
                    configuration));
        }

        /// <summary>
        /// Reads logger settings from the provided configuration object using the default section name. Generally this
        /// is preferable over the other method that takes a configuration section. Only this version will populate
        /// IConfiguration parameters on target methods.
        /// </summary>
        /// <param name="settingConfiguration">Logger setting configuration.</param>
        /// <param name="configuration">A configuration object which contains a Serilog section.</param>
        /// <param name="dependencyContext">The dependency context from which sink/enricher packages can be located. If not supplied, the platform
        /// default will be used.</param>
        /// <returns>An object allowing configuration to continue.</returns>
        public static LoggerConfiguration Configuration(
            this LoggerSettingsConfiguration settingConfiguration,
            IConfiguration configuration,
            DependencyContext dependencyContext = null)
            => Configuration(settingConfiguration, configuration, DefaultSectionName, dependencyContext);

        /// <summary>
        /// Reads logger settings from the provided configuration section. Generally it is preferable to use the other
        /// extension method that takes the full configuration object.
        /// </summary>
        /// <param name="settingConfiguration">Logger setting configuration.</param>
        /// <param name="configSection">The Serilog configuration section</param>
        /// <param name="dependencyContext">The dependency context from which sink/enricher packages can be located. If not supplied, the platform
        /// default will be used.</param>
        /// <returns>An object allowing configuration to continue.</returns>
        [Obsolete("Use ReadFrom.Configuration(IConfiguration configuration, string sectionName, DependencyContext dependencyContext) instead.")]
        public static LoggerConfiguration ConfigurationSection(
            this LoggerSettingsConfiguration settingConfiguration,
            IConfigurationSection configSection,
            DependencyContext dependencyContext = null)
        {
            if (settingConfiguration == null) throw new ArgumentNullException(nameof(settingConfiguration));
            if (configSection == null) throw new ArgumentNullException(nameof(configSection));

            var assemblyFinder = dependencyContext == null
                ? AssemblyFinder.Auto()
                : AssemblyFinder.ForDependencyContext(dependencyContext);

            return settingConfiguration.Settings(
                new ConfigurationReader(
                    configSection,
                    assemblyFinder,
                    configuration: null));
        }

        /// <summary>
        /// Reads logger settings from the provided configuration object using the provided section name. Generally this
        /// is preferable over the other method that takes a configuration section. Only this version will populate
        /// IConfiguration parameters on target methods.
        /// </summary>
        /// <param name="settingConfiguration">Logger setting configuration.</param>
        /// <param name="configuration">A configuration object which contains a Serilog section.</param>
        /// <param name="sectionName">A section name for section which contains a Serilog section.</param>
        /// <param name="configurationAssemblySource">Defines how the package identifies assemblies to scan for sinks and other Types.</param>
        /// <returns>An object allowing configuration to continue.</returns>
        public static LoggerConfiguration Configuration(
            this LoggerSettingsConfiguration settingConfiguration,
            IConfiguration configuration,
            string sectionName,
            ConfigurationAssemblySource configurationAssemblySource)
        {
            if (settingConfiguration == null) throw new ArgumentNullException(nameof(settingConfiguration));
            if (configuration == null) throw new ArgumentNullException(nameof(configuration));
            if (sectionName == null) throw new ArgumentNullException(nameof(sectionName));

            var assemblyFinder = AssemblyFinder.ForSource(configurationAssemblySource);

            return settingConfiguration.Settings(new ConfigurationReader(configuration.GetSection(sectionName), assemblyFinder, configuration));
        }

        /// <summary>
        /// Reads logger settings from the provided configuration object using the default section name. Generally this
        /// is preferable over the other method that takes a configuration section. Only this version will populate
        /// IConfiguration parameters on target methods.
        /// </summary>
        /// <param name="settingConfiguration">Logger setting configuration.</param>
        /// <param name="configuration">A configuration object which contains a Serilog section.</param>
        /// <param name="configurationAssemblySource">Defines how the package identifies assemblies to scan for sinks and other Types.</param>
        /// <returns>An object allowing configuration to continue.</returns>
        public static LoggerConfiguration Configuration(
            this LoggerSettingsConfiguration settingConfiguration,
            IConfiguration configuration,
            ConfigurationAssemblySource configurationAssemblySource)
            => Configuration(settingConfiguration, configuration, DefaultSectionName, configurationAssemblySource);

        /// <summary>
        /// Reads logger settings from the provided configuration section. Generally it is preferable to use the other
        /// extension method that takes the full configuration object.
        /// </summary>
        /// <param name="settingConfiguration">Logger setting configuration.</param>
        /// <param name="configSection">The Serilog configuration section</param>
        /// <param name="configurationAssemblySource">Defines how the package identifies assemblies to scan for sinks and other Types.</param>
        /// <returns>An object allowing configuration to continue.</returns>
        [Obsolete("Use ReadFrom.Configuration(IConfiguration configuration, string sectionName, ConfigurationAssemblySource configurationAssemblySource) instead.")]
        public static LoggerConfiguration ConfigurationSection(
            this LoggerSettingsConfiguration settingConfiguration,
            IConfigurationSection configSection,
            ConfigurationAssemblySource configurationAssemblySource)
        {
            if (settingConfiguration == null) throw new ArgumentNullException(nameof(settingConfiguration));
            if (configSection == null) throw new ArgumentNullException(nameof(configSection));

            var assemblyFinder = AssemblyFinder.ForSource(configurationAssemblySource);

            return settingConfiguration.Settings(new ConfigurationReader(configSection, assemblyFinder, configuration: null));
        }
    }
}
